1. Field
Apparatuses and methods consistent with exemplary embodiments relate to providing a backlight unit (BLU) and a liquid crystal display apparatus having the same, and more particularly, to providing a BLU that uses a quantum dot member as a fluorescent body, and a liquid crystal display apparatus having the same.
2. Description of the Related Art
A liquid crystal display (LCD) apparatus is an apparatus that realizes an image by using a liquid crystal and is implements as various types of display apparatuses such as a television (TV), a computer monitor, a smartphone display, a tablet, a smart wrist watch display, a smart glass display, etc.
A liquid crystal display apparatus may include a liquid crystal panel that displays light as an image and a light-emitting unit that provides light to the liquid crystal panel. The light-emitting unit may be referred to as a backlight unit (BLU).
A mercury discharge lamp such as an exterior electrode fluorescent lamp (EEFL), a cold cathode fluorescent lamp (CCFL), or the like may be used as the light-emitting unit. Alternatively, a light-emitting diode (LED) that may be capable of improving color reproduction without using silver (Ag) has been used as the light-emitting unit as well.
The light-emitting unit may be classified into a side light type and a direct type according to a position of a light source. The side light type refracts light from the light source, which is disposed on a side of the liquid crystal panel, to a light guide panel (LGP) which in turn provides the refracted light to the liquid crystal panel. The direct type provides light through a plurality of light sources that are disposed on a back side of the liquid crystal panel.
In the side light type light-emitting unit, the light emitted from the light source is guided such that the light is incident through the LGP and then is surface-emitted through total reflection and diffused reflection from select points in the LGP. The light surface-emitted from the LGP may be diffused and concentrated by optical sheets disposed on an upper side of the LGP, for example, by a diffuser sheet, a prism sheet, and a dual brightness enhancement film (DBE). Then the light is incident onto the liquid crystal panel.
The light-emitting unit may include a blue chip and/or other fluorescent bodies (red, green, yellow, white, etc.). The color representation ranges of the general fluorescent bodies may be limited. Thus, given that full width half maximums (FWHMs) of red light and green light are wide and may therefore affect other colors. Accordingly, the red light and the green light may not realize high color purities and color representations.
Also, although the light emitted from the light-emitting unit may be passed through a color filter, a sharp peak wavelength may still appear as shown in FIG. 1, and thus color representation may be lowered.
A light-emitting unit that uses a quantum dot member that has received attention as a fluorescent body that may improves light efficiency. However, a fluorescent characteristic of the quantum dot member is deteriorated due to heat discharged from a light source, and a lifespan of a produce is reduced.